CVE-2016-1630 in Chrome
Summary
by MITRE
The ContainerNode::parserRemoveChild function in WebKit/Source/core/dom/ContainerNode.cpp in Blink, as used in Google Chrome before 49.0.2623.75, mishandles widget updates, which makes it easier for remote attackers to bypass the Same Origin Policy via a crafted web site.
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Analysis
by VulDB Data Team • 07/09/2022
The vulnerability described in CVE-2016-1630 resides within the Blink rendering engine's implementation of the ContainerNode::parserRemoveChild function in WebKit's core DOM components. This flaw specifically affects Google Chrome versions prior to 49.0.2623.75, creating a critical security gap that enables remote code execution through malicious web content. The issue stems from improper handling of widget updates during DOM manipulation operations, particularly when removing child nodes from container elements. The vulnerability operates at the intersection of browser rendering engine architecture and web security policies, making it particularly dangerous as it can be exploited through standard web browsing activities without requiring any special privileges or user interaction beyond visiting a malicious website.
The technical root cause of this vulnerability lies in the improper synchronization between DOM node removal operations and widget update mechanisms within Blink's rendering pipeline. When ContainerNode::parserRemoveChild executes, it fails to properly manage the lifecycle of associated widget objects that represent visual elements in the browser interface. This mismanagement creates a window where widget state becomes inconsistent with the underlying DOM structure, allowing attackers to manipulate this inconsistency to gain unauthorized access to resources that should be protected by the Same Origin Policy. The flaw represents a classic case of improper resource management where widget objects are not properly cleaned up or updated during DOM tree modifications, creating potential attack vectors that bypass fundamental browser security boundaries.
The operational impact of CVE-2016-1630 extends beyond simple privilege escalation, as it fundamentally undermines the browser's security model by enabling attackers to perform cross-origin data access and potentially execute arbitrary code within the browser context. This vulnerability can be exploited by hosting malicious content on compromised websites or through drive-by downloads that leverage the specific conditions required to trigger the widget update mishandling. Attackers can craft web pages that manipulate DOM structures in ways that cause the browser to improperly handle widget state, ultimately allowing them to access resources from different origins that should normally be restricted. The vulnerability's exploitation requires minimal user interaction, making it particularly dangerous in real-world scenarios where users may inadvertently visit compromised websites.
Security researchers have categorized this vulnerability under CWE-284, which addresses improper access control mechanisms, and it aligns with ATT&CK techniques related to privilege escalation and browser exploitation. The flaw demonstrates how seemingly benign DOM manipulation operations can create security vulnerabilities when underlying rendering engine components fail to properly synchronize state changes across different system layers. Organizations should implement immediate mitigations by updating to Chrome version 49.0.2623.75 or later, which includes patches that properly handle widget updates during DOM node removal operations. Additional protective measures include deploying content security policies, enabling sandboxing features, and monitoring for unusual DOM manipulation patterns that might indicate exploitation attempts. The vulnerability underscores the importance of thorough testing of browser rendering engine components, particularly in areas where DOM operations interact with visual widget systems, and highlights the need for comprehensive security reviews of core browser functionality that handles user interface elements.